This invention relates to apparatus for injecting liquid-type material into the tobacco stream in the chimney of a cigarette maker. In particular, this invention relates to apparatus for injecting liquid additive foam into the tobacco accumulating on the suction tape in the chimney of a cigarette maker.
As is well known in the cigarette making art, most cigarette makers include a chimney section in which tobacco is sucked upward onto the underside of a perforated tape. The tobacco accumulates on the underside of the tape in a narrow channel between two rails on which the tape rides. The tape moves horizontally, carrying a stream of tobacco out of the chimney to subsequent sections of the cigarette maker. If one considers any particular length of the tape, the thickness of the layer of tobacco on that length of tape increases as the tape moves across the chimney, because the time the length of tape has been exposed to the tobacco flow increases. Therefore, the layer of tobacco on the tape is thickest at the point where the tape leaves the chimney.
It is also well known that material can be added to the tobacco stream in a cigarette maker, e.g., for purposes of binding or flavoring the cigarettes produced. Commonly-assigned U.S. Pat. No. 4,619,276 discloses that such material can be added in the form of a liquid foam at various points in a cigarette maker, including in the chimney, and particularly at the suction tape, after the tobacco has accumulated into a sufficient mass to accept the added material. It is disclosed in said commonly-assigned patent that a nozzle can be positioned just below and parallel to the suction tape for dispensing the liquid foam.
It has been found, however, that if such a nozzle is inserted into the suction tape channel of a standard cigarette maker chimney, the nozzle would interfere with the horizontal transport of tobacco by the suction tape and result in choking of the cigarette maker as tobacco built up behind the nozzle.
It would therefore be desirable to provide apparatus for injecting liquid-type material, including foamed liquid material or other liquid material, into the tobacco stream in the chimney of a cigarette maker without causing the maker to choke.